Catalytic processes for cracking liquid hydrocarbon streams, in particular heavy petroleum fractions, are well known. It is also known to recycle at least a portion of the produced gases (called off-gases) to the cracking reactor, generally in admixture with regenerated cracking catalyst. However, there is an ever present need to develop improved cracking processes resulting in enhanced yields of desired products (in particular gasoline) and in reduced formation of undesirable products (in particular coke).